Process of producing iron and steel.



S. McDONALD- PROCESS OF PRODUGMJG IRON AND STEEL.

APPLICATION FILED DEC- 6. 1916.

Patentefl Feb. 5, 1918.

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SAMUEL MCDONALD, 0F ALHAMBRA, CALIFORNIA.

IWESS OF PRODUCING IRON AND STEEL.

ducing iron and Steel, of which the following is a specification.

My invention relates to a process of pro ducing iron and steel from iron ore and steel scrap, or cast iron, and apparatus therefor; v 4

It isknown that iron or steel may be pro duced directly from the iron oreby melting the latter in a suitable electric furnace and refining the molten iron oxid by suitable reducing agents, such as carbon or hydro-car bon gases and the like. However, such a process has not proven a commercial success in all localities for the reason that the cost of electric power is too high. Furthermore, the reducing action is unsatisfactory because of the difficulty of quickly reducing the iron 'ore to iron or steel on a commercial scale and at a su'fiiciently low cost.

It is an object of this invention to provide a process of producing iron or steel, and apparatus therefor, in which a charge, of molten iron orsteel is covered with a layer of oxid of iron which, after being molten, is thoroughly mixed with the charge of iron and steel below bya current of non-oxidizing gas which carrieswith it powdered carbon. The carbon is partly dissolved in the charge of iron or steel. The dissolved carbon rapidly combines with the oxygen of the iron ore carried into the body of-the molten iron or steel by the current of nonoxidizing gas, thereby bringing about a rapid refining of the oxid iron ore. The reduction of the iron'orc is effected in a two-fold manner, by the combination of dis solved carbon in the charge of iron or steel just referred. to and by the direct action of the undissolved carbon on the oxid iron ore.

it is another object of this invention to provide a process of reducing iron ore or steel which. is rapid,easily carried on, low in cost, and which produces a superior product.

With the above and other objects in'view,

which will appear as the description proceeds, my invention consists in the steps of the process hereinafter described and the apparatus employed for carryingout said process.

In the accompanying drawings, which Specification of Letters Patent.

respectively for heating the furnace.

, central bore 24; of the twyer i2.

ran. a, 1918..

Application filed Becember 6, 1916. Serial No. 135,399.

form a part of this specification, l. havcillustrated a convenlent and practical apparatus for carrying on my process.

The figure of the drawing illustrates a.

transverse vertical section. of a furnace of a tilting type some parts. being shown in elevation for clearness of illustration, suitable for carrying out my new process.

10 designates the shell of the furnace which is preferably rectangular in shape, and hasa refractory basic lining 11 through which inclined openings or twyers 12 are provided. The furnace is charged by means of charging doors 13, below which a'spout 14, for pouringthe finished iron or steel, is,

situated. 30 and 31 are the gas and air ports The furnace is of the tilting type resting on anti friction rollers 15 carried on a suitable base 16. A suitable mechanism 17, which, in the present instance is shown to be a cylinder operating a rod 18 connected with the furnace, is provided, whereby the furnace may betilted. ,Horizontal pipe 19. for supplying pulverized carbon is provided in which a suitable scroll conveyor 20 is mounted and operated by any suitable means not shown. A vertical feed spout 21 provided with a suitable cut-off valve 22 leads to the mouthpiece 23 connected to the outer end of the A gas pipe 25 provided with a nozzle 26, projects into the mouthpiece 23 and serves to blow the carbon, or carbon fiber, or carbonaceous compounds through the central bore 2 1- into the charge of furnace. A valve 27 is provided in the nozzle 26 whereby the cun rent of gas may be controlled.

In carrying out my process, a charge of iron or steel scrap in sufficiently large amount to cover the bottom of the furnace,

quantity of oxid of iron ore is nova introduced into the furnace and forms a layer 29 on top of the bottom cha rge 28. The iron oxid ore is preferably heated or roasted, before its introduction into the furnace in order to expel-any moisture andperha s partially reduce the oxygen in the ore. T e

tit

- oxidizing the dissolved in the refined dition rapidly combines dit'ion to the reducing till t'urnace.

' dissolve the free nary iron oxid ore which usiially carries an of lime and silica whereby its melting point isreduced. After the iron oxid ore is molten the'saine is subjected to action as follows: lulverized any suitable kind which. however.

the reducing carbon ot 'must be sulliciently free from moisture, sul- .t'ur and other substances that might inpire the tinished product is "blown into the molten charge in quantities sutlicient to reduce the oxygen ofthe charge to the lowest possible practical point. By opening the valveZQ in the chute 21 and opening valve .27 in the nozzle :26, then tilting the furnace to the proper angle to bring the molten charge over the opening 24. the gas which is under suitable pressure will blow the carbon throughthc bore 24 of the twyer 12 into the molten charge. It should be noted that the direction of the current of gas and carbon is inclined to the level of the molten charge and toward the center of the bottom of the The gas that I propose to use in blowing the pulverized carbon into the. molten mass is natural or manufactured gas sullicieutly low in tree oxygen to prevent carbon. In place of the natural or manufiictured gas. any other non-oxidizing gas may lie used. It may be found advantageous to use air mixed with the g: s and carbon or air and carbon alone. There may he conditions when a little air mixed with gas may be more economical than gas'alone. The action of the current of gas mixed with the carbon as stated. Pill.

ries'the molten oxid down .and through the charge of refined iron lying directly under the, molten oxid. llic t'ree carbon is rapidly iron and in this conwith the oxygen of the iron ore and reduces the latter. in adaction of the dissolved carbon carried in by the gas will likewise combine with the oxygen of the inollcirorc and thus the iron ore is refined by, the action ot". the dissolved carbon in the refined iron and tree carbon carried in by the gu-is. it at any time it is found that the carbon content in the refined iron is too low. to reduce or react on the oxygen of the. molten ore with sullicient rapidity. the operator may tilt the furnace in such a position that the lower end of the gas inlet will carry the incoming carbon through the refined iron. which will rapidly ahsorh or carbon from the gas blast.

carbon. the free sary to do so to hasten the carbon in the incoming gas insures a rapid .deoxidation of the ore.

Various changes in the details of the construction and operation of my invention will occur to those skilled in the art. without (leparting from the spirit of my invention as claimed. such as pouring the tinished iron through spout ll. also pouring off the slag or gangne from time to time proceeds.

lVhile I have described here the process with the reduction of iron ores. it will be understoodthat the same is not limited time to. but may he used in connection with any other ores capable of such reduction.

Best results are obtained by using powdered carbon in connection with the nonoxidizing gas, but a reducing gas may be used alone without anycarbon in carrying out the process of reducing ores to a metallic state. v

small quantity of'o'il, preferably crude or partially retined mineral oil. may lie atomized and. blown into the charge by means of the gas current, either with or without the powdered carbonaceous material.

I claim:

1. process of )roducing iron or steel providing a body 0 as the process molten iron ore on to"p' ot' the molten charge of iron or stccl and gas against said iron ore whereby said iron ore is carried below the surface of". said charge and reduced to iron or steel.

'3. A process of producing iron or steel from iron ores. comprising melting o. iron ore on top of a molten charge of iron or steel. and blowing a non-oxidizing gas mixed with a powdered carbonaceous material against said iron ore whereby said iron ore is carried below the surface of said charge and reduced to iron or steel.

In testimony whereof I have signed my name to this specification.

a, body 

